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Barnum - water colour change solution


Ynot

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I've been looking for the effect used in Barnum where a glass of clear water 'miraculously' changes to a dark colour as he pours between two glasses...

Without knowing what it's called, I'm having difficulties locating a supplier.

 

I'm sure someone here will be able to give me the answer :)

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I don't remember the effect and there may be a standard way of doing it.

 

Wearing my ex*-chemistry teacher hat:

 

I'd try a phenolpthalein solution with a few drops of a dilute weak alkali(dilute baking soda?)in the other glass. Phenolphthalein is clear and colourless but turns pink/red in an alkaline environment. It's quite a powerful laxative so be careful with your risk assessment. You don't want someone drinking the phenolphthalein solution by accident.

 

Another option is very dilute Iron III Chloride and potassium thiocyanate. A few drops of freshly made FeCl3 solution in one glass and pour the potassium thiocyanate into it. It goes blood red. Again, take care with your risk assessment. Despite the 'cyanate' bit it's not too bad.

 

*Hooray!

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There's not an "off the shelf" version you can buy.

 

It's more commonly done with PH indicators and mild acids but to be honest your best bet is just to put a couple of drops of food colouring in the bottom of the empty glass- the action of pouring water in to it will mix it well enough and thus the entire effect will be 100% safe (nothing that "looks like" water but isn't), idiot proof and cost you less than £1 for the entire run

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:D

For those who've never seen the show here's the inimitable

in the original UK version... (apologies for the oriental subtitles - first one I found)

3 minutes in - tips water from a decanter into a glass, back into the decanter and repeats - the colour change to purple only happens after the 4th transfer, which of course makes the effect that more 'magical.

 

(And yes, this is one of the many things actually scripted in the show).

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My guess (as another ex chemistry teacher) is that this is an example of an 'Iodine Clock reaction'. If you google this and use the RSC link it will give you a suitable 'recipe'. I would contact your nearest school who will have all these chemicals and can advise aon the necessary RA. From the final colour it is probably carried out at very low concentration - the standard iodine clock can produce a delayed but very sudden change from colourless to blue black. However the colour of the starch-iodine complex is slightly purple at low concentration.
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If you consider the KISS solution of the food colouring, then couldn't some slight-of-hand be incorporated so the actor slips in the colouring?

Not sure how you'd do it unless the colouring was in a very fast dissolving capsule unaffected by skin moisture :unsure:

Ask a magician?

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Amusingly, as soon as the chemistry teachers (ex and current) started posting I kicked myself for not thinking of asking a little closer to home...

My youngest is on a year's break after her A levels and planning to go to uni to study chemistry... As soon as I asked her (after dragging her ass out of her bed ;o) she said exactly the same thing - the iodine clock reaction.

However, she's also struggling to understand how it might work as per the video - so I've set her the mission of investigating this for me. :)

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Many, many moons ago when I went to the open day of the school I ended up going to, we did that iodine clock reaction - whole group of students each with a slightly different "recipe" so that they would change at 10 second intervals. And amazingly (to an 11 year old!) they did change, down the bench, one by one, exactly 10s apart. Going by the video above, you'd just need to use the right chemical proportions and choreograph it so the change occurs at the right time.
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The initial reaction takes place in the first pouring, the second and third pouring are a distraction; what you're seeing there is an effect straight out of a victorian magic textbook. Because the reaction is so predictable the actor can simply time their actions so that it looks like the magic happens when they want it to.

 

I will stress again though - the "chemical" versions are technologically fun but are a more complicated reset, cost much more to implement and have safety implications - just about every show I've ever worked on with something that "looked like water" or which had an "ordinary" & "empty" cup in it was misused at some point by someone which means this is something you've got to do some extra RA paperwork for and actively take steps to prevent it from happening (ie the prop is locked away, not set until seconds before the scene starts and properly cleared away at the end) and in my experience the power of this effect is no different to a simple water and food colouring transformation; with the advantage that the latter is completely safe.

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If I could get big bucks for selling people GCSE chemistry reactions then I would, believe me :-p

 

Sadly working as many shows as I have (25th aniversary in the business this May) has exposed me to the multitude of idiots that lurk backstage on shows and shown that if you ever make anything look "normal" that isn't then more than one person will try and use it no matter how well you signpost it so a big chunk of my job is not having cool ideas but rather pre-planning for all the stupid things people will do when they switch off their brain and think that somehow the "magic" is all real.

 

Genuinely if I had been hired to do this particular production of Barnum my professional advice would be food colouring and water simply because the effect it produces is IDENTICAL to the chemical reaction methods but with absolutely no complications or risks. I'd justify my fee by coming up with a method to slightly delay the mixing (so the liquid could be poured back and fourth once or twice before changing) or I'd heighten the effect by having 7 glasses in a line and have him pour from a big jug in to each glass producing a different colour (the song is called "colours of my life" after all) so the effect takes on a new level.

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What about the dye used for tracing drains and sewer outfalls etc ?

 

It is very concentrated and an amount almost too small to see will colour a glass of water. Most colours are fluorescent and will be even more vivid if UV lighting is available. The same material is also carried in life rafts, in order to colour the sea around the raft a bright yellow and facilitate location from the air. A small package colours a vast area of the sea !

 

A fleabay search for "drain tracing powder" will reveal numerous suppliers. Be careful in handling it ! NOT due to any actual danger, but to avoid yourself and everything you touch becoming coloured.

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Fluorescein green is most common of he drain tracers, used as base for Chcago St Patricks day river dyeing...

 

http://mentalfloss.com/article/62220/what-do-they-use-dye-chicago-river-green-st-patricks-day

 

Bromofluorescein is orange and Rhodamine B is red

 

http://www.ebay.co.uk/itm/Fluorescent-Dye-Starter-Kit-5-dyes-fluoresceins-rhodamines-acridines/350525837782

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The initial reaction takes place in the first pouring, the second and third pouring are a distraction; what you're seeing there is an effect straight out of a victorian magic textbook. Because the reaction is so predictable the actor can simply time their actions so that it looks like the magic happens when they want it to.

 

I will stress again though - the "chemical" versions are technologically fun but are a more complicated reset, cost much more to implement and have safety implications - just about every show I've ever worked on with something that "looked like water" or which had an "ordinary" & "empty" cup in it was misused at some point by someone which means this is something you've got to do some extra RA paperwork for and actively take steps to prevent it from happening (ie the prop is locked away, not set until seconds before the scene starts and properly cleared away at the end) and in my experience the power of this effect is no different to a simple water and food colouring transformation; with the advantage that the latter is completely safe.

 

Hello!!

I worked on the Crawford production......It is a chemical 'mix' the carafe had one chemical in it and the tumbler had a small (very small) test tube on the back...look at his thumb move on second to last pour.....we were always told NOT to drink it ** laughs out loud ** however I always remember the ASM moaning cause the solution took some cleaning as it started to stain the glass.....

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